This invention relates to a novel fluorine-containing aromatic polyamide and production process thereof.
Aromatic polyamides have so far been used in the fields of fiber and coatings as an excellent material having a high strength, a high elastic modulus, a high heat resistance and a flame retardance.
On the other hand, fluorine-containing polymers are excellent in heat resistance, chemical resistance, water-repellent and oil-repellent properties, unstickness, etc. Making most of these unique properties, they are extensively used as a high-functionality polymer.
In the recent time, however, there is an intense desire to enhance the functionality of aromatic polyamides, such as improvement of moisture resistance, etc. As an aromatic polyamide granting such a request, an aromatic polyamide having hexafluoropropylidene groups in its molecular chain and an aromatic polyamide of which main chain involves aromatic rings with directly linked fluorine atoms are proposed for the reason of availability of starting materials, for example in Japanese Patent Application Kokai (Laid-Open) No. 62-169122. According to the finding of the present inventors, however, these aromatic polyamides cannot sufficiently fulfil the above-mentioned requirements.